EP2166773A1

EP2166773A1 - Digital multimedia recording system and corresponding recording method

Info

Publication number: EP2166773A1
Application number: EP08425624A
Authority: EP
Inventors: Piero Mortara
Original assignee: Magneti Marelli SpA
Current assignee: Marelli Europe SpA
Priority date: 2008-09-23
Filing date: 2008-09-23
Publication date: 2010-03-24
Anticipated expiration: 2028-09-23
Also published as: EP2166773B1

Abstract

A system for the recording of multimedia information is described, of the type including a position detection module (11), a digital recording module (20) of said multimedia information (AS, VS) and means of correlating said multimedia information (AS, VS) with positional information (P₁, P₂, P₃) provided by said position detection module (11). According to the invention, said recording module (20) includes recording said multimedia information (AS, VS) onto one or more recording tracks (TR₁... TR_n), said recording module (20) including at least one additional track (TR₀) for recording of said positional information (P₁, P₂, P₃) in a synchronised way with respect to said multimedia information (AS, VS) recorded on one or more recording tracks (TR₁... TR_n).

Description

The present invention concerns a system for the recording of multimedia information, of the type including a position detection module, a module for the recording of said multimedia information and means for correlating said multimedia information with positional information provided by said position detection module. Such multimedia information may include in particular audio and/or video and/or data information.
Systems allowing the recording of information and the execution of a georeferencing operation, associating positional information with recorded information are generally known.
For example, the Japanese patent publication JP2002340580 describes an information recorder provided with a function for the annotation of a desired vocal content, by means of the navigator apparatus onboard a vehicle. Such system acquires the voice by means of a microphone and the positional information at the instant of recording by means of a GPS system. The existence of vocal information at a certain geographic coordinate is then represented by means of an icon on the map of the navigator apparatus, so that by selecting the icon the vocal information is reproduced.
However, during survey operations, for example the reconnaissance of a route, the need arises for executing annotations that are connected to the position in which the annotation extensor is found and to successively reproduce them with an analogous temporal sequence. For example, this can occur in the context of the reconnaissance of the route of an automobile race, to write the route notes that will then be used by the team navigator to anticipate the turns, hills and other relevant route characteristics to the driver.
The present invention has the object of obtaining a multimedia recording system solution that allows the recording and successive reproduction of the multimedia information under the control of positional information associated with such multimedia information maintaining a precise control of the temporal sequence.
According to the present invention, such object is achieved by means of a recording system and a corresponding recording method, having the characteristics specifically recalled in the annexed claims.
The invention will now be described with reference to the annexed drawings, provided by way of non-limiting example only, wherein:

Figure 1 schematically represents a recording system according to the invention in a recording phase;
Figure 2 schematically represents the recording system according to the invention in a reproduction phase;
Figure 3 represents an illustrative diagram of an additional functioning mode of the system according to the invention;
Figure 4 represents a recomposition operation performed by the system according to the invention;
Figure 5 represents a schematic block diagram of a recording system according to the invention.

In brief, a system is proposed for digital multimedia audio and/or video and/or data recording and reproduction synchronized with data on the geographical position of the system itself, coming, for example, from a GPS receiver or other position detection system. The system records the audio and/or video and/or data information onto one or more digital recording tracks. The positional information, including position coordinates such as latitude, longitude and altitude, in the phase of recording of the audio/video signal are acquired and stored in parallel on an additional dedicated synchronization track.
In the reproduction phase, the system according to the invention employs such dedicated synchronization track to synchronize the reproduction of the multimedia track/s with the position of the system itself.
According to an aspect of the invention, it is envisioned that the limitations of precision of the position detecting system be considered and an equivalence comparison be carried out between a current or actual position and the position stored on the synchronization track.
Furthermore, the recording and reproduction phases being linked to position and not to time, these could occur even at very different speeds, therefore exhibiting the possible problem of temporal incompatibility with a correct and intelligible reproduction of the multimedia recording. According to a further aspect of the invention, in such case it is envisioned apply a time contraction or time-stretching procedure to adequately reassemble and manage the reproduction times of the multimedia tracks.
Figure 1 shows a schematic diagram of a recording system 10 in a recording phase. Such recording system 10 is partially shown herein with the elements required to illustrate the described operation phase, while a representation in schematic block form is visible in Figure 5.
Therefore, such recording system 10 includes a position detecting device 11 and a digital multimedia recorder 20. The position detecting device 11 is preferably a GPS satellite receiver, although it is possible to use other position detecting devices, such as an EGNOS satellite receiver.
The digital recording device 20 includes reproduction commands 21, for stopping the reproduction/recording 22 and for starting of recording 23. The digital recording device 20 operates by recording the multimedia signals on a plurality of tracks TR₁... TR_n. In particular, in Figure 1, a track TR₁ is provided for the audio data and a track TR₂ for the video data.
Furthermore, the digital recording device 20 includes an additional synchronization track TR₀ that is dedicated to the recording of positional information, as will be better illustrated later.
The recording operation occurs as follows.
When the operator actuates the start recording command 23 to send a first start recording signal SR₁, recording of the respective first audio AS₁ and video VS₁ segments is started. Under the control of the recording start signal SR₁ the position detecting device 11 acquires a first position P₁ where the recording starts. Such first position P₁ includes corresponding georeference coordinates C₁, including, for example, latitude, longitude and altitude.
In figure 1 the tracks TR₀, TR₁, TR₂... TR_n are shown parallel and spaced on the same time base so that the first position P₁ is stored on the synchronisation track TR₀ in temporal correspondence with the recording start of the first audio AS₁ and video VS₁ segments. Then the recording of the first audio AS₁ and video VS₁ segments is arrested by means of the reproduction/recording arrest command 22.
Then, in Figure 1 the second and third recording start signals, SR₂ and SR₃ respectively are represented, subsequently determining the recording of corresponding second audio AS₂ and video VS₂ segments and third audio AS₃ and video VS₃ segments onto the corresponding audio tracks TR₁ and TR₂. Upon each signalling of a recording start SR₂ and SR₃ a corresponding second position P₂ and third position P₃ is recorded, each including corresponding georeferencing coordinates C₂ and C₃.
Figure 2 instead represents the recording system 10 in a reproduction phase.
When operating the reproduction command 21, sending a reproduction signal SP, the position detector 11 acquires the current position PC and provides the corresponding current georeferencing coordinates CR to the digital recording device 20. The digital recording device 20 is configured to extract the positions P₁, P₂, P₃ stored on the synchronisation track TR₀ and to perform a comparison operation between the current position PC and each of the positions P₁, P₂, P₃ , represented by corresponding test blocks 71, 72, 73. The comparison operation of the test block 71, for example, evaluates whether such current position PC is equal to the position P₁. Additional details of the modes according to which such equivalence can be verified will be provided later in the description, in particular, with reference to Figure 3. Naturally, alternative methods are possible that envision performance of the comparison, for example, first with the first position P₁ recorded on the synchronisation track TR₀ and only successively applying the comparison to other positions in the case of a negative result.
In the affirmative case, an operation enabling reproduction of the first audio segment AS₁ and of the first video segment VS₁ is performed, represented by block 81. Analogous blocks 82 and 83 represent the operations enabling the segments AS₂, VS₂ and AS₃ and VS₃.
The position detector 11 acquires and provides the current position PC in a repeated or continuous way during the reproduction phase.
Figure 3, as was said, shows an illustrative diagram of a possible execution mode of the comparison operation 71, 72 or 73. The position detector 11, as was mentioned, provides the current position PC and the current coordinates CR of latitude, longitude and altitude. Indicating for simplicity latitude with the coordinate x, longitude with the coordinate y and altitude with the coordinate z, it is possible, for example, to consider a maximum error r with respect to the horizontal plane defined by the x and y coordinates. Any point P_i, P_j, P_k recorded on the synchronisation track TR₀ with coordinates x,y falling inside the circumference with radius equal to the maximum error r and having as its centre the current position PC, is considered valid for the comparison operation 71, 72 or 73, that is, it is considered equivalent to the current position PC. In this way, it is envisioned that the limitations in precision of the position detecting system be considered and an equivalence comparison be operated between a current or actual position and the position stored in the synchronisation track. For example, a system using a GPS position detector as detector may lead to errors of a few metres in the detection of the current position PC and in such case the window of equivalence will consequently have to be set to within a radius of at least 10 meters.
It is evident that, particularly if the comparison operation is performed as an equivalence comparison, the recording and reproduction phases being also linked to the position and not to time could occur even at very different speeds, consequently having the problem of possible temporal incompatibility with the correct and comprehensible multimedia reproduction of the recording.
In this case, it is necessary to suitably apply a time contraction or time-stretching procedure to adequately recompose and manage the reproduction times of the multimedia tracks.
For this purpose, in Figure 4 a diagram represents one next to the other the phases of recording, above, and reproduction, below, so that the tracks are represented on the same time scale. For simplicity, only the recorded audio track TR₁ and corresponding synchronisation track TR₀ are represented in the recording phase. NR indicates recorded intervals of silence on the audio track TR₁, that is, the nonrecorded intervals between the audio segments AS₁, AS₂, AS₃. On the temporal axis t, instants of time are indicated T₁, T₂, T₃ in correspondence of which the recordings of the audio segments AS₁, AS₂, AS₃ are performed upon reaching the positions P₁, P₂, P₃. For the reproduction phase, as can be seen, time instances t'₁, t'₂, t'₃ coinciding with when the corresponding positions P₁, P₂, P₃, are reached during reproduction or the positions considered to be equivalent to them, are represented on the temporal axis t. As can be seen, the coincidental time instances t'₁, t'₂, t'₃ are closer in time, for example, because we are moving faster with respect to the movement speed used during the recording phase. This leads to the reproduction of a reproduced audio track TR'₁ providing corresponding contracted audio segments AS'₁, AS'₂, AS'₃. NP represents intervals of silence in the reproduction on the reproduced audio track TR'₁ between the corresponding audio segments AS'₁, AS'₂, AS'₃, which are also contracted with respect to the recorded intervals of silence NR.
Such contraction operations on the multimedia tracks can be performed based on the prediction of the time instants t'₁, t'₂, t'₃, corresponding to when positions P₁, P₂, P₃, or the positions considered to be equivalent to them, will be reached during the reproduction. Such predictions can be performed, for example, by operating a measurement or an estimation of the speed of movement of the auto vehicle, means of transport or person equipped with the proposed system. In other words, by processing speed information, for example, coming from the speedometer of the auto vehicle, it is envisioned to perform predictions relative to the coincident time instants t'₁, t'₂, t'₃. In the case in which it is envisioned to reach, for example, the coincident time instant t'₂ before the reproduction of the audio segment AS₁ is finished, the contraction of such audio segment AS₁ into a contracted segment AS'₁ is provided for, for example, by operating proportionally to the estimated mean speed. It is clear that such contraction can be obtained by a corresponding increase of the reproduction speed of the audio segment or the adoption of other contraction techniques can be envisioned to contract its duration, such as, for example, the removal of possible pauses and intervals of silence in the audio segment AS₁. Analogous operations can be performed on possible video tracks.
Constructively, the system can be realised as a low-cost electronic unit with the basic elements as represented in Figure 5.
Thus Figure 5 represents an electronic unit indicated in its entirety with 30, including a position detector 11, as well as elements associated with the digital recorder 20, that is, a video camera 31, a microphone 32 and a speaker 33, exchanging data, under the control of a microcontroller 39, with a memory 38. The microcontroller 39 can also be accessed by digital signal inputs 37 and analogue inputs 36, through a connector 41. The system also includes a power supply 34 and a battery 35.
Naturally, the operation principles can conveniently be used integrated by way of non-limiting example in a satellite navigation system which is normally already provided with the required basic components.
Therefore, the advantages of the proposed solution are clear.
The system according to the invention advantageously allows the recording and successive reproduction of multimedia information under the control of positional information associated with such multimedia information, maintaining precise control of the temporal sequence. This occurs in particular recording onto one or more digital traces the information and onto an additional synchronised trace the positional information at which the recording of determined multimedia information starts.
Naturally, without prejudice to the underlying principle of the invention, the details of construction and the embodiments may vary widely with respect to what has been described and illustrated by way of example only, without departing from the scope of the present invention.
In the system, the number of multimedia tracks is limited only by the memory capacity; multiple tracks can be recorded and reproduced simultaneously and/or individually selected.
Such a system may find a possible use as road route reconnaissance apparatus, by way of non-limiting example only, for example for performing reconnaissance of the route of an automobile race.
In the reconnaissance phase the system advantageously allows recording in real-time in a way synchronised with the vehicle position, vocal indications describing a detail of the route, for example, regarding the type and radius of a turn and relative travel speed, surface condition and slope of the road, possible hidden obstacles.
The reproduction phase, used instead during training or during the race, allows the verbal indications to be received coherently synchronised with the vehicle position along the segment of interest.
The proposed system can therefore conveniently be used in diverse contexts (for example, terrestrial, nautical, river navigation, aeronautical) and applications (for example, reconnaissance of routes for purposes of competition, tourism, investigation or mission reporting).
It is also clear that the reproduction system may not necessarily be incorporated in the recording system, but constitute a separate system and/or one that can be operated separately, that receives recorded multimedia information through communication channels via cable or wireless or on recoding media, such as, for example compact disk, DVD, FLASH memory keys.

Claims

A system for the recording of multimedia information, of the type that includes a position detection module (11), a digital recording module (20) of said multimedia information (AS, VS) and means for correlating said multimedia information (AS, VS) with positional information (P₁, P₂, P₃) provided by said position detection module (11), characterised in that said recording module (20) includes recording said multimedia information (AS, VS) onto one or more recording tracks (TR₁... TR_n), said recording module (20) including at least one additional track (TR₀) for the recording of said positional information (P₁, P₂, P₃) in a synchronised way with respect to said multimedia information (AS, VS) recorded on one or more recording tracks (TR₁... TR_n).
The system according to claim 1, characterised in that said recording module (20) is configured to store said positional information (P₁, P₂, P₃) on the synchronisation track (TR₀) in temporal correspondence with the start of the recording of respective between said multimedia information (AS, VS).
The system according to claim 1 or 2, characterised in that said recording module (20) is configured to reproduce said multimedia information, extract the positions (P₁, P₂, P₃) stored on the synchronisation track (TR₀), perform a comparison operation (71, 72, 73) between the current position (PC) and one or more of the positions (P₁, P₂, P₃) stored on the synchronisation track (TR₀) to evaluate whether said current position (PC) is equal or equivalent to said one or more stored positions (P₁, P₂, P₃) and enable (81, 82, 83) in the affirmative case, the reproduction of recorded multimedia information synchronised with said stored position (P₁, P₂, P₃)_.
The system according to claim 3, characterised in that said position detector (11) is configured to acquire and provide the current position (PC) in a repeated or continuous way during the reproduction phase.
The system according to claim 3 or 4, characterised in that said comparison operation (71, 72, 73) evaluates said current position (PC) as being equivalent to said one or more stored positions (P₁, P₂, P₃) if it falls inside of a circumference having a radius equal to a defined maximum error (r), and having as its centre the current position (PC).
The system according to one or more of the previous claims, characterised in that said recording module (20) is configured to apply a time contraction procedure during said reproduction phase to compensate for differences in moving speed between the recording phase and the reproduction phase.
The system according to claim 6, characterised in that said time contraction procedure includes generating upon reproduction one or more multimedia information tracks (TR'₁) including multimedia information (AS'₁, AS'₂, AS'₃) contracted temporally and/or intervals of silence (NP) contracted temporally with respect to the corresponding recorded intervals of silence (NR).
The system according to one or more of the previous claims, characterised in that it is included in or associated with a road route reconnaissance apparatus.
A method for the recording of multimedia information, including detecting the position (11), recording digitally said multimedia information (AS, VS) and putting in correspondence said multimedia information (AS, VS) with positional information (P₁, P₂, P₃) provided in said position detection operation (11), characterised in that
it also includes recording said multimedia information (AS, VS) onto one or more recording tracks (TR₁... TR_n) and making available at least one additional track (TR₀) for the recording of said positional information (P₁, P₂, P₃) in a synchronised way with respect to said multimedia information (AS, VS) recorded on one or more recording tracks (TR₁... TR_n).
The method according to claim 9, characterised in that it includes storing said positional information (P₁, P₂, P₃) onto the synchronisation track (TR₀) in temporal correspondence with the start of the recording of corresponding among said multimedia information (AS, VS).
The method according to claim 9 or 10, characterised in that it includes reproducing said multimedia information, extracting the positions (P₁, P₂, P₃) stored on the synchronisation track (TR₀) and performing a comparison operation (71, 72, 73) between the current position (PC) and one or more of the positions (P₁, P₂, P₃) stored on the synchronisation track (TR₀) to evaluate whether said current position (PC) is equal or equivalent to said one or more of the stored positions (P₁, P₂, P₃) and to authorise (81, 82, 83) in the affirmative case the reproduction of recorded multimedia information synchronised with said stored position (P₁, P₂, P₃).
The method according to claim 11, characterised in that it includes providing the current position (PC) in a repeated or continuous way during the reproduction phase.
The method according to claim 11 or 12, characterised in that said comparison operation (71, 72, 73) evaluates said current position (PC) as being equivalent to said one or more stored positions (P₁, P₂, P₃) if it falls inside of a circumference having a radius equal to a defined maximum error (r), and having as its centre the current position (PC).
The method according to one or more of the previous claims from 8 to 13, characterised in that it includes applying a time contraction procedure during said reproduction phase to compensate for differences in moving speed between the recording phase and the reproduction phase.
The method according to claim 14, characterised in that said time contraction procedure includes reproducing one or more multimedia information tracks (TR'₁) including multimedia information (AS'₁, AS'₂, AS'₃) contracted temporally and/or with intervals of silence (NP) contracted temporally with respect to corresponding recorded intervals of silence (NR), in particular, said contraction procedure being performed based on the prediction of coincidental time instants (t'₁, t'₂, t'₃) in correspondence of which the respective positions (P₁, P₂, P₃) stored on the synchronisation track (TR₀) will be reached.